Separation of sulphonates



Patented-Nov. 21,1939 i I? r 2,180,728

o STATES A m creme SEPARATION OF SULPHON'ATES Frank W. Corkery, Grafton, Pa.,assignor to Pennsylvania. Industrial Chemical Corporation, a corpora ion of Pennsylvania No Drawing. Application March 16, 1937,

Serial No. 131,182

4 Claims; (Cl. 260-503l- This invention relates to the separation from tillation of the heavier cuts of No. 1 and No. 2 the still residue, hereinafter defined, of metallic crude solvent naphtha. Usually the still residue sulphonates present in such still residue. is subjected to a distillation for the removal of 1 These sulphonates, separated from thev other solvents and naphthalene. '5 ingredients of the still residue, are a good base To recover sulphonates from such still resi- 6 material for extreme pressure lubricants, and due, while purifying the still residue, I desirhave other uses in the arts. ably pursue the following preferred method:

The still residue from which the sulphonates A low boiling aliphatic solvent, such as keroare separated is resultant from the treatment sene, V. M. P. naphtha, Stoddard solvent, ligroin,

10 of. light oil derived in the by-product coking or gasoline, desirably a petroleum distillate of 10 p of coal. Such light oil comes over in coal disthe gravity and boiling point known as mineral tillation, and is'recovered from the gases with spirits, is run into a treating tank and'is agiwhich it comes over by being absorbed in scrub tated, as by means of a mechanical agitator. bing oil which is ordinarily a heavy cut of pe- The still residue is then run into the tank, and

troleum. I is agitated with the-petroleum distillate until a 15 The still residue with which I deal results from precipitate forms. Desirably, in this step the fractionation and purifying treatment of this volume of petroleum distillate is approximately light oil, following its removal from the scrubtwice the volume of the still residue. bing oil. This still residue contains polymers Beforethe precipitate has a chance to coagu- 0 of resin-forming bodies in various stages of polylate, water is run in, and is agitated with the '20 merization, some heavy monomers, traces. of body of liquid in the tank. This liquid itself naphthalene, and various percentages of sulcontains in solution the aromatic hydrocarbon phates and sulphonates. It is a dark viscous and resinous contents of the still residue, and oily substance-deficient in drying qualities, and the introduction of water by'wetting the preitself possessing little utility in the arts. As it cipitate prevents its agglomeration. During this 25 is commercially available, the still residue may stageof the operationthe mixture in the treatbe obtained from either of the following operaing tankis at normal room temperature, at tions conducted upon the light oil. slightly elevated temperature, or at a tempera- One such source of still residue is thestill in mm somewhat below normal room temperature.

which the light oil is purified and fractionated 'Either in the initial treatingfltank, or more 30 to give crude benzol, crude toluol, No. 1 crude efliciently after running it into a. plurality of solvent naphtha (crude xylol), and No. 2 crude settling tanks, the treatment of the mixtureis solvent naphtha The d m-f m t s fraccontinued. If the mixture is transferred to a tionation consists largely of heat polymers, and plurality of settling tanks,vdesirably the transis known in the trade as crude still residue. fer is made with the introductionvoi live steam .35 The fractions from the crude still, after washinto the mixture, and with agitation; and steaming h Sulphuric acid and neutralized, are S-, ing and agitation may be continued for a short tilled in What are known in the trade as pure period of time to insure: completion of the sludge stills. The residues from the distillation of precipitation, and to prepare the mixture for fractiOnS comprise Primarily d p lystratification on settling. The dispersion of live 0 mBIS d t l Y and c p e o SlJlsteam through the mixture is desirable forthe ph t resultantv from acid pu ifi n an reason that it speeds up the rate ofsettling. alkaline neutralization of the light oil. The resi- If r t be u d, t use -f-steam.ma,y dues from the pure still contain also somecombe omitted; I

pounds of the alkali and alkaline earths, includ- Upon being allowed to .settle Stratification ing their sulphates resultant from neutralization takes place in the mixture. The water content,

following acid purification 0f h light This. the water initially added and that supplied by p Still es due normally is mixed in a tan condensed steam if steam be used, floats the soluwith the crude still residue, so that, as it is comtion of still residue in petroleum distillate, I to mercially available, still residue contains at least produce well defined stratification. In the wathe residual products from these two types of 'ter layer there is a settled mass of precipitate.

still dealing with coke-oven light oil and its frac- As the. final stage of my preferred separation tions. Usually there is also mixed in with these method, the petroleum distillate solution of still two still residues in the residue tank a third residue is decanted to leave water and sludge in 555 residue, which comprises bottoms from the disthe tank, or tanks. Purified still residue is recovered from solution in the petroleum solvent by distillation, as described in my co-pending application Serial No. 120,192, filed January 12, 1937. Any retained traces of solvent in the sludge are then steamed off, and the water is removed by blowing with warm air. The sludge which remains is a greasy substance, which is desirable as a base for extreme pressure lubricating compounds. While it apparently comprises a small content of sulphates and other substances, it is preponderantly composed of sulphonates of aromatic bodies native'to the light oil by treatment of which the still residue is formed. I am unaware of the exact chemical composition of these sulphonates, but it is apparent that they comprise alkali or alkaline earth salts of sulphonates of the light oil aromatics.

Upon test I have found that this sulphonate sludge, as it is produced, possesses the fundamental qualities necessary in an extreme pressure lubricant. When tested in the Timken extreme pressure testing machine it does not show any sign of failure when the machine indicates a value of 100 on its scale, each unit of which is supposed to indicate a pressure of 1000 pounds. Upon moderate heating, under the effects of extreme pressure or otherwise, it shows very slight thinning tendency. At high temperatures the sulphonatesludge shows a tendency to harden, and this hardening presents an obstacle to its use as a single-substance extreme pressure lubricant base for some purposes.

Considering the sulphonate sludge as of itself, the remarkable fact concerning it is that it, normally considered, is a waste product (sludge) recovered from what has until recently been considered a waste product (still residue from the treatment of coal-derived light oil). As a waste product, recovered from a Waste product, I yet have discovered that it possesses strikingly valuable potentialities.

While it has been stated above that I am unaware of the exact composition of the sulphonate sludge, which together with dipolymer oil forms my extreme pressure base, it has certain readily observable physical characteristics additional to those given above. Thus it has no resinous properties; it possesses only slight thermoplasticity; and is not tacky. It does not tend to separate, and has no definite melting-point. As recovered from the still residue, of which it forms approximately 14% of the initial content, by the method above described, it is soft and can be readily pumped and handled.

As a division of this application there has been filed application Serial No. 205,302, filed April 30, 1938. p

I claim as my invention:

1. The herein described method of recovering sulphonate sludge from still residue resultant from the treatment and distillation of light oil derived from the by-product coking of coal and containing water-insoluble sulphonates formed by acid purification and alkaline neutralization in the light oil prior to distillation, which consists in precipitating sulphonates from the still residue by agitating the still residue with low boiling aliphatic hydrocarbon, wetting the pre cipitate by agitating the mixture with water before the precipitated sulphonates coagulate, effecting stratification of the mixture and settling of the precipitate expedited by injection of live steam into the mixture to form a water layer containing the sulphonates and a hydrocarbon layer containing the other still residue ingredients in solution, separating the layer of still residue solution and the sulphonate-containing water layer, and by drying recovering the sulphonates as a residual sludge.

2. The herein described method of recovering sulphonate sludge from still residue resultant from the treatment and distillation of light oil derived from the by-produot coking of coal and containing water-insoluble sulphonates formed by acid purification and alkaline neutralization in the light oil prior to distillation, which consists in pursuing in sequence the steps of precipitating sulphonates from the still residue by mixing low boiling aliphatic hydrocarbon with the still residue, wetting the precipitate by agitating the mixture with water before the precipitated sulphonates coagulate, effecting stratification of the mixture and settling of the precipitate to form a water layer containing the sulphones and a hydrocarbon layer containing the other still residue ingredients in solution, separating the layer of still residue solution and the sulphonate-containing water layer, and by drying recovering the sulphonates as a residual sludge.

3. The herein described method of recovering sulphonate sludge from still residue resultant from the treatment and distillation of light oil derived from the by-product coking of coal and containing water-insoluble sulphonates formed by acid purification and alkaline neutralization in the light oil prior to distillation, which'consists in pursuing in sequence the steps of precipitating sulphonates from the still residue by mix ing low boiling aliphatic hydrocarbon with the still residue, wetting the precipitate by agitating the mixture with water before the precipitated sulphonates coagulate, effecting stratification of the mixture, and settling of the precipitate expedited by injection of live steam into the mixture to form a water layer containing the sulphonates and a hydrocarbon layer containing the other still residue ingredients in solution, separating the layer of still residue solution and the sulphonate-containing water layer, and by drying recovering the sulphonates as a residual sludge.

4. The herein described method of recovering sulphonate sludge from still residue resultant from the treatment and distillation of light oil derived from the by-product coking of coal and containing water-insoluble sulphonates formed by acid purification and alkaline neutralization in the light oil prior to distillation, which consists in precipitating sulphonates from the still residue by agitating the still residue with low boiling aliphatic hydrocarbon, wetting the precipitate by agitating the mixture with water before the precipitated sulphonates coagulate, effecting Stratification of the mixture and settling of the precipitate to form a water layer containing the sulphonates and a hydrocarbon layer containing the other still residue ingredients, separating the layer of still residue solution and the sulphonate containing water layer, and by drying recovering the sulphonates as a residual sludge.

FRANK W. CORKERY. 

